/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.activemq;
import java.util.
ArrayList;
import java.util.
LinkedList;
import java.util.
List;
import org.apache.activemq.command.
MessageDispatch;
public class
FifoMessageDispatchChannel implements
MessageDispatchChannel {
private final
Object mutex = new
Object();
private final
LinkedList<
MessageDispatch>
list;
private boolean
closed;
private boolean
running;
public
FifoMessageDispatchChannel() {
this.
list = new
LinkedList<
MessageDispatch>();
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#enqueue(org.apache.activemq.command.MessageDispatch)
*/
public void
enqueue(
MessageDispatch message) {
synchronized (
mutex) {
list.
addLast(
message);
mutex.
notify();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#enqueueFirst(org.apache.activemq.command.MessageDispatch)
*/
public void
enqueueFirst(
MessageDispatch message) {
synchronized (
mutex) {
list.
addFirst(
message);
mutex.
notify();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#isEmpty()
*/
public boolean
isEmpty() {
synchronized (
mutex) {
return
list.
isEmpty();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#dequeue(long)
*/
public
MessageDispatch dequeue(long
timeout) throws
InterruptedException {
synchronized (
mutex) {
// Wait until the consumer is ready to deliver messages.
while (
timeout != 0 && !
closed && (
list.
isEmpty() || !
running)) {
if (
timeout == -1) {
mutex.
wait();
} else {
mutex.
wait(
timeout);
break;
}
}
if (
closed || !
running ||
list.
isEmpty()) {
return null;
}
return
list.
removeFirst();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#dequeueNoWait()
*/
public
MessageDispatch dequeueNoWait() {
synchronized (
mutex) {
if (
closed || !
running ||
list.
isEmpty()) {
return null;
}
return
list.
removeFirst();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#peek()
*/
public
MessageDispatch peek() {
synchronized (
mutex) {
if (
closed || !
running ||
list.
isEmpty()) {
return null;
}
return
list.
getFirst();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#start()
*/
public void
start() {
synchronized (
mutex) {
running = true;
mutex.
notifyAll();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#stop()
*/
public void
stop() {
synchronized (
mutex) {
running = false;
mutex.
notifyAll();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#close()
*/
public void
close() {
synchronized (
mutex) {
if (!
closed) {
running = false;
closed = true;
}
mutex.
notifyAll();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#clear()
*/
public void
clear() {
synchronized (
mutex) {
list.
clear();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#isClosed()
*/
public boolean
isClosed() {
return
closed;
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#size()
*/
public int
size() {
synchronized (
mutex) {
return
list.
size();
}
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#getMutex()
*/
public
Object getMutex() {
return
mutex;
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#isRunning()
*/
public boolean
isRunning() {
return
running;
}
/* (non-Javadoc)
* @see org.apache.activemq.MessageDispatchChannelI#removeAll()
*/
public
List<
MessageDispatch>
removeAll() {
synchronized (
mutex) {
ArrayList<
MessageDispatch>
rc = new
ArrayList<
MessageDispatch>(
list);
list.
clear();
return
rc;
}
}
@
Override
public
String toString() {
synchronized (
mutex) {
return
list.
toString();
}
}
}